The term for any act that endangers children's emotional or physical well-being is

Child abuse

Explanation:

Child abuse is any act that puts at risk the emotional and physical well-being of a child

nasa 3

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."